Thiophenecarbonylalkylene-diamines



United States Patent cc 3,505,338

Patented Apr. 7, 1970 3 505 338 The compounds of this invention are preferably pre- THIOPHENECARB0l IYLlLKYLENE-DIAMINES pared by the meflmd' William Blythe Wright, .lr., Woodcliif Lake, N.J., and 1 Herbert Joseph Brabander, Nanuet, N.Y., assignors to American Cyanamid Company, Stamford, Conn., a 5 R -H-C0N0.\H2..X HB corporation of Maine I No Drawing. Continuation-impart of application Ser. No. s

596,831, Nov. 25, 1966. This application Jan. 15, 1968,

Ser. No. 697,611

Int. Cl. C07d 51/70 us. Cl. 260293.4 4 Claims 10 Rt j-OOIII-CJIn-B ABSTRACT OF THE DISCLOSURE wherein R, R R B and n are as defined above and X is Preparation of substituted N- (tert. -arninoalkyl)thioa halogen, q yls lfonyloxy 0r monocyclic arylsulphenecarboxamides by reacting a halogen, lower a1ky1Su1 fonyloxy radical. The reaction takes place when the refonyloXy or monocyclic arylsulfonyloxy substituted alkylagents are contacted in an inert S lVent such as ether, enethiophenecarboxamide with a substituted arylheterotetrahydroffuran P a the llke, and the cyclic o d, i d jb o h methods f prepar reagent mixture is mamtamed wlthin the temperature of ing substituted N-(tert.-a-minoalkyl)thiophenecarboxamfrom about 500 to C for a Penod of 10 minutes to ides are described. The substituted N-(tert.-aminoalkyl) Several hoursthiophenecarboxamides are useful for their central nerv- The compounds of the Present mventlon F also be Gus System (CNS) depressant properties prepared by other methods. One of these involves the preparation of a reactive thiophenecarboxamide as an intermediate followed by reaction with the amine:

This invention is a continuation-in-part of our copend- R1 ing application Ser. No. 596,831, filed Nov. 25, 1966, now N 0 N abandoned. R-E *00011 SUMMARY OF THE INVENTION This invention relates to new organic compounds. More R1 particularly, it relates to N-(tert.-aminoalkyl)thiophene- I carboxamide derivatives and methods of preparing the R LH I same.

The novel compounds of the present invention may be s/ illustrated by the following formula: RI

0 R1 R l lNCnH uB I fi' I R l oN o.H2.B s a S wherein R, R R n and B are as defined above.

This reaction is best carried out in two steps and tetrahydrofuran is a satisfactory solvent. A temperature range wherein R and R are selected from the group consisting of 25-75" C. is most desirable.

of hydrogen, lower alkyl and halogen; R is selected from In still another method, the acid and amine are mixed the group consisting of hydrogen, lower alkyl, and lower and a carbodiimide derivative is added to effect condensaalkenyl; n is an integer from 2 to 4 and B is selected from tion:

the group consisting of 1-aryl-4-piperaziny1, 4-arylpiperiwherein R, R R n and B are as herein-before defined. dino and 4-aryl-3,6-dihydro-l (2H)-pyridyl, in which the This reaction may usually be carried out within a temaryl group is selected from the group consisting of phenyl, perature range of 25100 C. and the product is isolated lower alkoxyphenyl, lower alkylthiophenyl, lower alkylby procedures well known to the art. phenyl, halophenyl, and trifiuoromethylphenyl; and the Thiophenecarboxamides may also be used as intermedipharmaceutically acceptable acid addition salts thereof. ates for alkylation procedures:

The free bases of this invention may be either liquids or solids at room temperature. The free bases are, in general, relatively insoluble in water, but soluble in most or- I ganic solvents such as lower alkyl alcohols and esters, 001173 X CHH2BB acetone, chloroform, and the like. These compounds form 5 R2 acid addition salts with strong acids, such as hydrochloric acid, sulfuric acid, perchloric acid, and the like. The compounds also form salts with organic acids, as for example, fumaric and maleic acid. Such salts, in general, are

l R soluble in water, methanol and ethanol, but relatively int, soluble in benzene, ether, petroleum ether, and the like.

wherein R, R R B and n are as defined hereinbefore and X is a reactive halogen, lower alkyl sulfonyloxy or monocyclic arylsulfonyloxy group. The amide is dissolved in an inert solvent, such as for example, diethyleneglycol dimethyl ether (diglyme) and treated with a condensing agent such as sodium hydride and then with an appropriate aminoalkyl derivative. The reaction may be best carried out at temperatures within the range of about 30- 200 C. for a period of from 30 minutes to 6 hours.

A further method of preparing the present compounds can be illustrated by the following procedures:

wherein R, R R B and n are as defined hereinbefore.

In this process, a thiophenecarboxylic acid is treated with a halogenating agent such as thionyl chloride or phosphorous pentachloride, usually at room temperature in an inert solvent. The thiophenecarboxylic acid chloride is isolated and reacted with an alkylenediamine derivative. The products are recovered and purified by recrystallization from a suitable solvent. Alternatively, an acid anhydride in place of the acid chloride may be prepared as the intermediate.

The compounds of the present invention show central nervous system (CNS) depressant properties when given to Warm-blooded animals. This activity is indicated by several procedures. For example, a test which indicates hypnotic and/or muscle relaxant type activity is represented by the following rod walking test. Groups of 6 mice each are tested for their ability to Walk across a horizontal rod in a normal manner after receiving graded interperitoneal doses of a compound. A median effective rod walking dose (RWD) is estimated.

A test which indicates tranquilizing activity is represented by a measure of the reduction in motor activity. One half of the (RWD) dose is given to a group of 5 mice and a 5 minute count of motor activity is recorded (actophotometer). Counts of 2250 are considered to indicate a specific reduction (more than two standard deviations) of activity at a dose causing only minimal impairment of neurological function as measured by rod walking ability. Compounds that appear to reduce motor activity (2250 count) are administered to additional groups of 5 mice at graded doses and tested similarly. The motor depression dose (MDD) which causes a 50% reduction of motor activity (a count of 250) is estimated. The use of reduced motor activity as a measure of tranquilizing activity has been described by W. D. Gray, A. C. Osterberg and C. E. Rauh, Archives Internationales et de Therapie, vol. 134, p. 198 (1961) and by W. I. Kinnard and C. J. Carr, Journal of Pharmacology and Experimental Therapeutics, vol. 121, p. 354 (1957).

As a test for toxicity or margin of safety, the compounds that did specifically reduce motor activity are given to 10 mice at a dose of 10X MDD. The compounds that did not reduce motor activity are given to 10 mice at a dose of 4 RWD. If more than 50% of the mice die within 24 hours, the compound is rejected for reasons of toxicity or low margin of safety. If 250% of the mice die, the compound is considered interesting for further study.

The (CNS) activity of representative compounds when tested by the above procedures is summarized in the following table:

TABLE I l t a 'CNCnHznB.HCl

Safety percent dead/ MDDso, RWDao, dose, R R1 n B mg/kg. nag/kg. mgfkg.

H H 2 O 1.2 0.2 0at12.

H H 2 1 2.1 2.2 50at200.

H n: 2 N Q-o1 14 40 Oat 140.

H H a N 2.6 30 0:11:26.

H H a N --o1 0 40 Oat 0o.

H H 2 N N- 0 00 at112.

H H 2 N N a 10 Oat 30.

(31 a 11 H 2 N N 4 0at300.

11 11 2 N N- --or 12 100 Oat 120.

TABLE-Continued Safety percent dead/ MDDo, RVVDm, (1089, R R1 n B mg./kg. mg./kg. mgJkg.

:1 H H 2 N N@ 1.4 000 14.

m H H 2 N N-CH3 100 10at260.

(l)CHa H H 2 N N 9.3 50 0:11:93.

H H 3 N N 2 24 00020.

H H 3 N N@-o1 4 100 0at40.

5-01 H 2 16 N@ 8 100 0at80.

5-Br H 2 rt N@ 9 100 00090.

a H CH3 2 N N@ 50 36 Oat 144.

The products of the present invention can be incorporated in various pharmaceutical forms such as tablets, capsules, pills, and so forth, for immediate or sustained release, by combining with suitable carriers. The daily dose may vary from 10 mg. to 1000 mg. dependent upon the warm-blooded animal. They may be in the form of dosage units for single therapeutic dose or in small units for multiple dosages or in larger units for division into single doses. Obviously, in addition to the therapeutic agent, there may be present excipients, binders, fillers and other therapeutically inert ingredients necessary in the formulation of the desired pharmaceutical preparation.

DETAILED DESCRIPTION The following specific examples illustrate the preparation of representative compounds of the present invention. Parts are by weight unless otherwise indicated.

EXAMPLE 1 Preparation of N-[2;-(4-phenyl-1-piperazinyl)ethyl]-2- thiophenecarboxamide A solution of 23.6 parts of 2-thenoylchloride in 200 parts of chloroform is added to a mixture of 34.5 parts of 2-bromoethylamine hydrobromide and 46 parts of sodium carbonate in 200 parts of water. The reaction mixture is stirred for 4 hours and the layers are separated. The aqueous layer is extracted with additional chloroform and the combined chloroform layers are dried over magnesium sulfate and concentrated to remove the solvent. The crystalline residue is recrystallized from benzene and N-(2-brom0ethyl)-2-thiophenecarboxamide, melting point 133-134 C., is obtained.

A mixture of 5.7 parts of N-(2bromoethyl)-2-thiophenecarboxamide, 7.5 parts of l-phenylpiperazine and 200 parts of benzene is heated at reflux temperature for 5 hours and cooled. The benzene solution is washed with water and then dried over magnesium sulfate and concentrated to remove the solvent. The residue is triturated with hexane and the solid product is filtered off and then recrystallized from benzene by addition of ether. The N- [2- (4-phenyl-1-piperazinyl) ethyl] -2 thiophenecarboxamide melts at 132-134 C. When the above compound is dissolved in benzene and ethanolic hydrogen chloride is added, the hydrochloride salt is obtained, melting point 241-243 C.

EXAMPLE 2 Preparation of N- [2- 3,6-dihydro-4-phenyl- 1- (2H) pyridyl) ethyl] -2-thiophenecarboxamide The above compound, melting point 112 C., is obtained When 4-phenyl-1,2,5,6-tetrahydropyridine is substituted for l-phenylpiperazine in the procedure of Example 1. The hydrochloride salt melts at 224-227 C.

EXAMPLE 3 Preparation of N-[2-(4-m-trifluoromethylphenyl-l-piperazinyl) ethyl] -2-thio henecarboxamide When 1-(m-trifluoromethylphenyl)piperazine is substituted for l-phenylpiperazine in the procedure of Example 1, the above compound melting point 148-l50 C., is obtained. The hydrochloride melts at 242244 C.

EXAMPLE 4 Preparation of N-[2-(4-p-chlorophenyl-3,6-dihydro-1- (2H) -pyridyl) -ethyl] -2-thiophenecarboxamide If 4 -(p-chloro phenyl)-1,2,5,6-tetrahydropyridine is substituted for l-phenylpiperazine in the procedure of Example 1, the above compound, melting point 163-165" C., is obtained. The hydrochloride salt melts at 247- 250 C.

EXAMPLE 5 Preparation of N- 3-(4-phenyl-1-piperazinyl)-propyl]- Lthiophenecarboxamide residue is recrystallized from benzene by addition of hexane. The N -(3-brornopropyl)-2-thiophenecarboxamide melts at 4649 C.

A mixture of 6 parts of N-(3-bromopropyl)-2-thiophenecarboxamide, 7.9 parts of l-phenylpiperazine and 200 parts of benzene is heated at reflux temperature for hours and cooled. The benzene layer is washed with Water, dried over magnesium sulfate and concentrated to remove the solvent. The residue is triturated with hexane and the crystalline product is filtered ofi. Recrystallization from benzene by addition of hexane results in N-[3-(4- phenyl-l-piperazinyl)propyl] 2 thiophenecarboxamide melting at 1l7l19 C. The hydrochloride melts at 193 196 C.

EXAMPLE 6 Preparation of N-[3-(4-p-chlorophenyl-l-piperazinyl) propyl]-2-thiophenecarboxamide The above compound, melting point 142-144 C., is obtained when 1-(p-chlorophenyl)piperazine is substituted for l-pherlylpiperazine in the procedure of Example 5 The hydrochloride melts at 226-228" C.

EXAMPLE 7 Preparation of N 3- 3,6-dihydro-4-phenyl-l-(2H) pyridyl) propyl1-2-thiophene carboxamide When 4-phenyl-1,2,5,6-tetrahydropyridine is substituted for l-phenylpiperazine in the procedure of Example 5, the above compound, melting point 103-105 C., is obtained. The hydrochloride melts at 193-195 C.

EXAMPLE 8 Preparation of N-[3-(4-p-chlorophenyl-3,6-dihydro-1- (2H) -pyridyl) propyl] -2-thiophenecarboxamide This compound, melting point 127-l29 C., is obtained when 4-(p-chlorophenyl) 1,2,S,6 tetrahydropyridine is substituted for l-phenylpiperazine in the procedure of Example 5. The hydrochloride melts at 197199 C.

EXAMPLE 9 Preparation of N-[2-(4-phenylpiperidino)ethyl]-2- thiophenecarboxamide The above compound is obtained when 4-phenylpiperidine is substituted for l-phenylpiperazine in the procedure of Example 1. The hydrochloride melts at 236238 C.

EXAMPLE 10 Preparation of N-[2-(4-m-chloropheny1piperidino) ethyl]-2-thiophenecarboxamide When 4-(m-chlorophenyl)piperidine is substituted for l-phenylpiperazine in the procedure of Example 1, the above compound is obtained.

EXAMPLE 11 Preparation of N-[2-(4-m-trifiuoromethylphenylpiperidino)ethyl]-2thiophenecarboxamide The above compound is obtained when 1-phenylpiperazine is replaced by 4-(m-trifiuoromethylphenyl)piperazine in the procedure of Example 1. EXAMPLE 12 Preparation of N-[2-(4-p-tolylpiperidino)ethyl]-2- thiophenecarboxamide If 4(p-toly1)piperidine is substituted for l-phenylpiperazine in the procedure of Example 1, the above compound is obtained.

EXAMPLE 13 Preparation of N- [2- (4-phenyl-1-piperazinyl) ethyl] -3- thiophenecarboxamide The above compound is obtained when N-(Z-bromoethyl)-3-thiophenecarboxamide is treated with l-phenyl-y piperazine by the procedure of Example 1.

EXAMPLE 15 Preparation of N-[2-(4-phenyl1piperazinyl)ethyl]-3,5- dichloro-Z-thiophenecarboxamide If 3,5-dichloro-2-thenoyl chloride is substituted for 2- thenoyl chloride in the procedure of Example 1, this compound is obtained. 7

EXAMPLE 16 Preparation of N-[2-(4-phenyl-1-piperazinyl)ethy1]-4- chloro-S-ethyl-2-thiophenecarboxamide The compound is obtained when 4-chloro-5-ethyl-2- thenoyl chloride is substituted for thenoyl chloride in the procedure of Example 1.

EXAMPLE 17 Preparation of N-[2-(4-phenyl-1-piperazinyl) ethyl]-5- fluoro-2-thiophenecarboxamide When S-fluoro-Z-thenoyl chloride is substituted for thenoyl chloride in the procedure of Example 1, this compound is obtained.

EXAMPLE 18 Preparation of N-[2-(3,6-dihydro-4-phenyl-l-(2H)- pyridyl ethyl] 5-chloro-2-thiophenecarboxamide The above compound is obtained when N-(Z-bromoethyl)-5-chloro-2-thiophenecarboxamide is treated with 4- phenyl 1,2,5,6 tetrahydropyridine by the procedure of Example 1.

EXAMPLE 19 Preparation of N-[2-(4-p-chloropheny1-I-piperazinyl) ethyl] -2-thiophenecarboxamide hydrochloride The above compound, melting point 259'262 C., is

obtained when l-(p-chlorophenyl)piperazine is substituted for l-phenylpiperazine in the procedure of Example 1.

EXAMPLE 20' Preparation of N-[2-(4-m-tolyl-l-piperazinyDethyH-Z- thiophenecarboxamide When 4- (m-tolyl)piperazine is substituted for l-phenylpiperazine in the procedure of Example 1, this compound is obtained. The hydrochloride melts at 259-262 C.

EXAMPLE 21 Preparation of N-[2-(4-m-chlorophenyl-l-piperazinyl) ethyl] -2-thiophenecarboxamide If 1-(m-chlorophenyl)piperazine is substituted for lphenylpiperazine in the procedure of Example 1, this compound is obtained. The hydrochloride melts at 256- 259 C.

EXAMPLE 22 Preparation of N-[2-(4-p-tolyl-1-piperazinyl)ethyl]-2- thiophenecarboxamide hydrochloride The above compound, melting point 264-267 C., is obtained when 1-(p-tolyl)piperazine is substituted for l-phenylpiperazine in the procedure of Example 1.

EXAMPLE 23 Preparation of N-[2-(4-m-methoxyphenyl-l-piperazinyl) ethyl] -2-thiophenecarb oxamide This compound is obtained when l-(m-methoxyphenyl)-piperazine is substituted for 1-pheny1piperazine 9 in the procedure of Example 1. The hydrochloride melts at 231-233" C.

EXAMPLE 24 Preparation of N-[2-(3,6-dihydro-4-rn-trifluoromethylpheny1-1-(2H) -pyridyl) ethyl] -2-thiophenecarboxamide When 4- (m-trifiuoromethylphenyl) -1,2,'5,6-tetrahydro pyridine is substituted for l-phenylpiperazine in the procedure of Example 1, this compound is obtained.

EXAMPLE 25 Preparation of N-[4-(4-phenyl-1-piperazinyl)butyl]-2- thiophenecarboxamide The above compound is obtained when N-(4-bromopropyl)-2-thiophenecarboxamide and l-phenylpiperazine are treated by the procedure of Example 1.

EXAMPLE 26 Preparation of N methyl N [2 (4 m trifiuoromethylphenyl 1 piperazinyl)ethy1] 2 thiophenecarboxamide hydrochloride A mixture of 15.4 parts of l-(m-trifluoromethylphenyD-piperazine, 6.8 parts of N-(2-chloroethyl)-N- methyl-2-thiophenecarboxamide, and 150 parts of benzene are heated at reflux temperature for 8 hours and then filtered. The mother liquor is concentrated to remove the solvent. The residue is washed several times with hexane and then dissolved in ether. Alcoholic hydrogen chloride is added and a precipitate forms. The precipitate is filtered off and recrystallized twice from ethanol. The N methyl N [2 (4 m trifluorolnethylphenyl 1- piperazinyl)ethyl] -2-thiophenecarboxarnide hydrochloride melts at 192194 C.

EXAMPLE 27 Preparation of N-a1lyl-N-[2-(4-phenyl-1-piperazinyl) ethyl] -2-thiophenecarboxamide The above compound is obtained when l-phenylpiperazine and N-allyl-N-(Z-chloroethyl)-2-thiophenecarboxamide are reacted by the procedure of Example 26.

EXAMPLE 28 Preparation of N-[2-(4-phenyl-1-piperazinyl)ethyl]- 2-thiophenecarboxamide hydrochloride A mixture of 15 parts of 1-(2-aminoethyl)-4-phenylpiperazine, 25 parts of sodium carbonate, 150 parts of water and 300 parts of benzene is cooled and stirred as a solution of 10 parts of 2-thenoyl chloride in 100 ml. of benzene is added. The mixture is stirred for hours and the layers are separated. The benzene layer is washed with water and then concentrated. The residue is triturated with hexane and the solid product is filtered off and recrystallized from benzene by addition of ether. The product is dissolved in benzene and ethanolic hydrogen chloride is added. The crystalline product is filtered off and melts at 241243 C.

EXAMPLE 29 Preparation of N-[2-(4-m-methylthiophenyl-l-piperazinyl) ethyl] -2-thiophenecarboxamide This compound is obtained when l-(m-methylthiophenyl)-piperazine is substituted for l-phenylpiperazine in the procedure of Example 1.

1 0 EXAMPLE 30 Preparation of 5-chloro-N-[2-(4-pheny1-1-piperaziny1) ethyl] -2-thiophenecarboxamide A mixture of 6.80 parts of S-chlorothiophene-Z-carboxylic acid, 7.50 parts of N,N'-carbonyldiimidazole, and 50 parts of tetrahydrofuran is allowed to stand at room temperature for one hour and 8.55 parts of 2-(4- phenyl-l-piperazinyl)ethylamine is added. The mixture is left at room temperature overnight, the solvent is distilled off, and 250 parts of 0.2 N sodium hydroxide is added. The mixture is extracted with chloroform and the chloroform layer is concentrated. The residue is recrystallized from ethyl acetate in order to obtain the 5-chloro-N-[2- (4 phenyl 1 piperazinyl)ethyl] 2 thiophenecarboxarnide, melting point 162-164 C. The hydrochloride salt melts at 245-247 C.

EXAMPLE 31 Preparation of 5-brormo-N-[2-(4-phenyl-l-piperaziny1) ethyl] -2-thiophenecarboxamide tt es s R wherein R and R are selected from the group consisting of hydrogen, n-lower alkyl and halogen; R is selected from the group consisting of hydrogen, lower alkyl and lower alkenyl; R is hydrogen, lower alkoxy, lower alkyl, thio-lower alkyl, halo and trifluoromethyl; n is an integer from 2 to 4, is a single .or double bond and pharmaceutically aceptable acid addition salts.

2. The compound in acordance with claim 1: N-[2- (3,6 dihydro 4 phenyl 1 (2H) pyridyl)ethyl] 2- thiophenecarboxamide.

3. The compound in accordance with claim 1: N-[3- (3,6 dihydro 4 phenyl 1 (2H) pyridyl)propyl] 2- thiophenecarboxamide.

4. The compound in accordance with claim 1: N-[2-(4- phenylpiperidino) ethyl] -2-thiophenecarboxamide.

References Cited UNITED STATES PATENTS 2,647,120 7/1953 Williamson 260268 X 2,684,369 7/1954 Leonard 260-268 X 3,005,821 10/1961 Hayao 260-268 3,030,366 4/1962 Biel 260268 DONALD G. DAUS, Primary Examiner U.S. Cl. X.R. 260-268, 294.8, 309, 332.2; 424250, 263, 267 

